Effects of different capture techniques on the physiological condition of bonefish Albula vulpes evaluated using field diagnostic tools

Abstract

A study was conducted on bonefish Albula vulpes in The Bahamas to assess the utility of portable physiological diagnostic tools (i‐STAT analyser with E3+ ion and haematology cartridge, ACCU‐CHEK glucose meter and Lactate Pro lactate meter) for field physiology applications in remote locations. Physiological values derived from portable diagnostic tools were significantly related to values obtained from standard laboratory techniques [glucose ( r 2 = 0·96), packed cell volume (PCV; r 2 = 0·33), Na + ( r 2 = 0·28), K + ( r 2 = 0·71) and Cl − ( r 2 = 0·15)]. Actual values ( i.e. intercepts), however, tended to deviate slightly between the two techniques. Nonetheless, these tools showed promise for documenting relative differences among fishes experimentally exposed to treatments inducing different levels of ‘stress’. These tools were then used to characterize the effects of different capture techniques on the stress response of A. vulpes . Albula vulpes captured in seines and then temporarily held in pens were physiologically sampled between 1 and 45 min postcapture to evaluate postcapture stress dynamics. Blood glucose and lactate as well as PCV and haemoglobin (Hb) increased rapidly after capture but stabilized at maximal values by c. 20 min postcapture. When angled, larger A. vulpes took longer to exhaust and land than did smaller individuals. In addition, there was a positive relationship between the magnitude of increase in lactate and the duration of the angling event, implying that anglers can reduce stress by minimizing the duration of the fight. Fish sampled before and after a simulated angling treatment displayed clear increases in blood lactate, K + , PCV and Hb, providing some of the first data on how individual A. vulpes respond to angling stress. In summary, this study revealed that techniques are now available for conducting field physiological studies on A. vulpes and possibly other species in remote locales, and that haematological and biochemical indicators of physiological disturbance vary with the intensity of the angling event.

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